(CNN) — A moment of silence was observed at 10:30 a.m. Pacific Time, the exact moment when JFK was shot and killed 50 years ago.

Thousands will gather for a memorial ceremony Friday in Dallas.

President Obama and the first lady laid a wreath at his gravesite in Arlington National Cemetery. Fifty years later that eternal flame still burns.

A new JFK monument will be unveiled during Friday’s ceremony. It is located in the ground on the infamous grassy knoll. The inscription on the monument is the final paragraph of the speech JFK intended to deliver on Nov. 22, 1963.

Click on the video above to watch ABC’s live special coverage of the anniversary.